The present invention relates generally to escalators and, in particular, to a safety apparatus for the elimination of the gaps between the tread surface and/or the riser of a step and stationary pedestal plates located along both sides of a treadable stair belt of an escalator.
Various prior art safety devices for escalators are known for preventing accidents due to wedging-in of articles between the movable steps and adjacent stationary pedestal plates. Some such devices use colored markings along the danger zone of the side edges of the step tread surfaces. Other devices place protective profiles on the outermost lateral edges of the tread surface. Still other devices have upwardly projecting lateral end ribs on the tread surfaces or completely close off of the clearance between the side edges of the steps and the pedestal plates with synthetic material inserts.
One such safety device is shown in U.S. Pat. No. 4,519,490 and has synthetic material bearing means which are clamped securely onto the outermost or onto the adjacent lateral rib of the tread surfaces of the steps. A projecting portion slides against the metal pedestal plates and covers the clearance between each step and the pedestal plate and/or closes it completely by a lateral insert body. In the latter case, a synthetic material of low coefficient of friction relative to the pedestal plates is used. However, the synthetic material parts clamped onto the ribs of the tread surfaces require a relatively large lateral play during the passage of the steps through the combs in the upper and lower horizontal running region of the stair belt.
A disadvantage of the above-described device is that the clamped synthetic material parts can be displaced in the direction of travel of the steps or even torn out of the clamped mounting. There is increased wedging risk due to the lateral play enlarged by an absent or displaced synthetic material part, and increased wedging risk in the region of the entry of the step into the comb through the larger openings required to accommodate the increased lateral play.
The present invention solves the problems associated with the prior art safety devices by providing a protective device which is positioned on both sides of the steps, is firmly and immovably connected with the step and requires no significant enlargement of the entry clearances in the region of the step entry into the comb.